Air-cleaning material and process of making the same



Nov 18,-

C. P. HEGAN AIR CLEANING MATERIAL AND PROCESS OF MAKING THE SAME Filed March 27 1924 Fatente'd Flo v.18, 1924.

- UNITE TATES -TENT orFlcE,

cKEsTEE Ii-HEGAN, E LooIsvILLE, KENTUCKY, ASSIGNOR TO REED Am EILTEE oomramnor LoUIsvrLLE, KENTUCKY, A CORPORATION or KENTUCKY.

him-CLEANING MATERIAL AND PROCESS or MAKING THE SAME.

Application fled March 27f, 1924; Serial No. 702,405. I v

1267 First Street, Louisville, in the county 6 of Jefierson and State of Kentucky, have invented certain new and useful Improve merits in Air-Cleaning-- Materials and Processes of Making the Same, of which'the following isa s ecification.

1 The inventlon relates to a1r'cleaningma terial "of the 'sameg'eneral type as that described in the patent to Reed,'No. 1,483,379, Feb. 12, 1924.

An objector the inventlon is to "provide 7 a fibrous mass of air cleaning material, the

individual metal fibers ofwhich are protected by and bonded together by a metallic film. A further object ofthe-invention is to providea metal coated fibrous mass in WhlCl'l the percentage of voids progressively decreases iromone faceto the 0 po'site'face. of the 'mass.' The invention a o .c'ontemf plates a novel method of forming a filtering mass having the characteristics" specified above.- v

It is well recognized that fibrous material such as steel wool is a very efiicient medium forthe cleansing of air and gas, particularly when the fibrous material is 80 coated with oil or. other viscous fluids.

Filters formed'of meta-1 fibers are open to.

the objection howeverlthat'the individual I fibers may shift position'or mat down with a resultant increase 1n the air resistance. 85' As the individual fibers are fragile, they break up while in use, and such breakage mayresult in the formation of cracks extending'through the mass, especially after the fibers have become more or 'less closely 40 matted. Itis obvious 'thatsuchmatting or cracking of the filter mass renders the 'filter ineflicient or inoperative and that the mass must be discarded since it cannotbe, restored to its original efliciency by the usual. a

before coating the metal wool. Apparatus cleaning processes.

To overcome these 'diflicnlties, 1- bond the 7 individual fibers to each other by coating the fibers with, a 'metal or alloy, which is.

referabl acid and 'corfrosion resistant, 450v he meta coating upon the fibers bonds the mass into an integral structure which w ll retain its shape and arrangement under the severest conditions of use, such for example as are encountered when the filter is located at the intake of an air compressor; The in-,

dividual fibers arereinforced by the metal coating and will not be broken by the re-- peated pulsations set up by the compressor. Thefibrous mass is preferably assembled in a filter cell or-unit before the coating operation and the entire'cell is immersed in pickling baths of the usual type, then in a flux such as zinc chloride solutlon and finalremoved in various ways, such as by shaking, by forcing the cell into'a bath of heated .oilor by blowing'superheated air through 'the cell.

For a better understanding of the novel air cleaning material and the process of producing the same, attention is'called to the accompanying drawing, in which Fig. 1 is a sectional view of a filter cell containing fibrous material 'embodying my invention; I v

Fig. 2 isa diagrammatic view of apparatus which may be employed in forming the filtering material.

In the drawings, the numeral 1 designates the open frame of a filter unit or cell within which is arranged a mass of fibrous ma terial 2. Wire screens 3, or other foraminous sheets are providedat the inlet and outlet faces of the frame to support the fibrous materialbefore and during the coatly in a bath of molten metal or alloy, for, A

for coating the assembled units is 'shown diagrammatically inliig.g2, and comprises a flux tank 4, a tank 5 ',for holding} the ly by cams 8, an d a tan k 9 for holding hot the oven. The chute 15 preferably consists water into which the coated cell is. discharged for cleaning and cooling. The shaking mechanism is located within a hood or oven 10 through which pass the products of combustion from the heaters arranged beneath the several "tanks, arid; the 'oven is provided with a damper ll'for regulating the oven temperature. The inlet door 12 *and' outlet door 13 of the oven swing shut by gravity and may be opened by the pressure or impact of acell against the doors.

The filter cells may'be conveyed to the coat-" ing. apparatus from the pickling vats, not

shown, by an overhead traveler 14, which traveler is also used for handling the filters during the coating process. After immersion in the flux tanks, the cells are transferred to the metal tank, and after a short immersion are then transferred to an inclinedchute 15 from which they slide into metal fibers when the filter is removed from the molten bath. The excess metal drains from the filter, passing through the grating 6 into a pan 17. After a sufficient time, the loose grating 6 is tipped by any convenient means to an angle sufiicient to cause the filter to slideby gravity against the outlet door 13, which: opens under the impact and allows the filter to slide into the tank 9 for cooling and rinsing. The removal and drying ofthe filter .complete the process.

Due to the use of products of combustion for heating the oven, the freshly deposited coating does not oxidize but remains as a bright, impervious metallic film upon the individual fibers. The fibers are protected against corrosion and are bonded together so firmly that they will not shift position, mat or break under hard usage. A further and exceedingly desirable result is obtained when metal fiber is treated by this process, i. e.,' the fibers are more dense, at one side of the filter than atthe other. By lifting the cell from the molten bath in a horizontal position and with the inlet face of the cell up, the excess metal in draining from the cell packs the fibers tighter at the oulet face of the cell. The progressive decrease in the percentage of voids which is thus secured results in a more even distribution of the collected solids throughout the filter and allows the collection of the maximum amount of material withthe lowest resistance to air or flow.

The same results may be obtained when the excess metal is removed b superheated air through the cell from the inlet face, the cell being arranged horizontally and with the inlet face up or by forcing the cell into a bath of heated oil.

It will fbe "apparent that the vafziation 'in density which is "secured by the novel process of treating a mass of metal fibers of subby regulation-of the temperature inthe oven or the rate at which the excess metal is drained or forced from'the 'metal fibers.

lVhile I have specified a particular leadantimony alloy Ias'a' preferred coating mastantially uniformdensity may be controlled:

terial. it will be understood that these metals may be alloyed in varying proportions or. thatother metals or alloys may be employed.

Any one of the metals or alloys which may. '3

serve to bond themetal'fibers together, and render them less frangible is to be considered as a coating mejtal, as such term is employed in the following claims.

I claim:

1. A filter mass comprising 'metal fiber,

the fibers of which are bonded'together h. f

a metallic coating which covers the indivi ual fibers. 2. A filter mass comprising metal fiber, the individual fibers-of which are; covered with and bonded together by a coating of a different metal.

3. A filter mass as claimed in' claim 2 in which the coating metal comprises a leadantimony alloy.

4. A filter mass. comprising metal fiber,

the density of said mass progressively varying from one face to the other face of said I mass. and means for maintaining the varying density of said mass.

5. A filter mass as claimed in claim 4, wherein said means comprises a film of metal coating the individual fibers of said mass.

6. A filter cell comprising an open frame, foraminous sheets covering the faces of the frame. and a body' of metal fibers filling said frame, the individual fibers being coated with and bonded together by a different metal.

7. A filter cell as claimed in claim 6 wherein said body' of coated metal fibers progressively increases in density from the inlet towards the outlet face of the cell.

8. A filter cell as claimed in claim 6 wherein said metal fiberscomprise steel wool and said coating metal comprises a lead-antimony alloy.

9. A filter cell comprising an open frame, foraminous sheets covering the faces of said frame, and a body of metal fiber filling said frame, said metal fiber being of rogr'essively increasing density from the mlet towards the outlet face of said cell and the individual fibers of said metal fiber being coated with and bonded together by a leading the excess metal from the face at which antimony alloy. I the least density is desired towards and 10. The process of producin filter maout of the body of metal fiber at the face 10 terial of progressively varying ensit from at which the greatest density is desired. 5 a body of metal fiber of substantia y uni-' In testimony whereof, I aflix my signeform densit which comprises dipping the ture. metal fiber in a bath of metal, and displae- CHESTER P. .HEGAN. 

